The novel opens with the narrator, Jean Louise “Scout” Finch, relating that when her brother Jem was thirteen he broke his arm badly at the elbow. Scout withholds the exact cause of his accident, transitioning instead to her memories of the events leading up to Jem’s injury and their childhood in Maycomb, Alabama in the 1930s. Scout tells the story as an adult, but within the narrative she is a little girl who’s just six years old at the beginning of the novel and eight years old at the end. Her brother is four years older than her, and her father, Atticus Finch, is an attorney and member of the State Legislature who is, for the most part, well-respected in the community. Their friend, Charles Baker Harris, commonly referred to as “Dill,” visits every summer and becomes one of the primary sources of humor in the novel.
Other characters include Miss Maudie, the wise neighbor who spends most of her time gardening and baking cakes; Calpurnia, the African American servant who cares for the Finch children and runs the household; and Aunt Alexandra, who’s excessively critical of the other characters in the novel—especially Scout. Of the three, Scout has perhaps the best relationship with Miss Maudie, who teaches her valuable life lessons and explains that Atticus is an upstanding man. Calpurnia, being Scout’s caregiver and a disciplinarian, is a major figure in Scout’s life and instructs her on manners, morals, and the divide between whites and African Americans. Atticus, however, is the Finch children’s moral compass, and it’s from him that they learn to read, think, and react to the world. On Christmas, he gives them air rifles as presents, but admonishes them never to shoot a mockingbird, because it’s a sin to kill something that does nothing but make beautiful music for everyone. This is the source of the novel’s title.
It becomes clear early on that Scout isn’t like the other girls in Maycomb. For one, she primarily wears boy clothes and isn’t interested in acting like a “lady.” On the first day of school, she has a confrontation with her teacher, Miss Caroline, who doesn’t know that one of Scout’s classmates, Walter Cunningham, is from a poor family and won’t accept charity. When Scout tries to explain this, Miss Caroline strikes her hand, effectively whipping her in front of the class. For this, Scout grinds Walter’s face into the dirt and blames him for getting her in trouble at school. Throughout the first half of the novel, Scout gets into fights with people, including her own cousin, who says bad things about Scout’s father Atticus, and her brother, who doesn’t want Scout to talk to him at school—only after school. Nevertheless, Scout and Jem remain close and play together at the house when they aren’t at school.
Scout, Jem, and Dill spend most of the summer playing elaborate games, and these end up being the subject of the next few chapters of the novel. One of their favorite games is a reenactment of an incident between their neighbor, Boo, and his father, Mr. Radley. According to town lore, Boo was sitting at a table, cutting up some papers, when suddenly he took up the scissors and stabbed his father in the thigh as he was walking past. No reason is given for his outburst, and because of it the children are afraid of Boo to the point where they run past his house to avoid being in front of it. In one scene, Dill dares Jem to touch the Radleys’ house, and in another, Scout accidentally rolls into the Radleys’ yard in a tire after Jem pushes her much too hard. This incident leads Boo to start leaving presents (soap dolls, pennies, gum) for Scout and Jem in a knothole in the tree by their house, and this in turn leads the children to become curious about Boo and develop a sort of friendship. When Miss Maudie’s house burns down, Boo slips out of his house to place a blanket on Scout’s shoulders without her noticing. Without meeting face to face, the two characters form a special bond.
There are, however, moments of extreme peril in Part I. In addition to Miss Maudie’s house fire, there are mentions of animals being tortured by a character named Crazy Addie, of houses being broken into, and of course the attack on Mayella. Jem, Scout, and Dill have a brush with death when they sneak into the Radleys’ backyard and get shot at by Mr. Nathan Radley. In the process of fleeing, Jem gets his pants caught and has to leave them behind. Nathan Radley, assuming that he was shooting at an African American man trespassing on his property, doesn’t realize that the children were trying to sneak a peek inside his house, and to make sure nobody finds out about it, Jem goes back for his pants. When he does, he finds that someone has mended them for him and left them on the fence. In Chapter 10, the children are again confronted with death when a rabid dog, Tim Johnson, walks unsteadily down the street. Atticus, whom Scout previously referred to as “feeble,” reveals himself to be an excellent shot when he puts the dog out of his misery. Once upon a time, Atticus even had the nickname “One-Shot Finch.” This impresses Scout and alters her opinion of him forever.
Meanwhile, tensions heighten in Maycomb after Atticus is assigned to defend Tom Robinson, an African American man accused of raping a white woman, Mayella Ewell, the eldest daughter of Mr. Bob Ewell, one of the town drunks and perhaps the poorest white man in town. Being a man of high moral principles, Atticus refuses to pass on the case to another lawyer and instead stands firm in his conviction to defend Tom. Scout and Jem respect him for this, but the rest of the town doesn’t, and people gossip about it incessantly. Mrs. Dubose, a mean old woman who sits out on her porch and shouts at passersby, says such terrible things about Atticus that Jem cuts down her camellias with Scout’s baton. His punishment for this is to read to Mrs. Dubose every afternoon. During these visits, Mrs. Dubose lies in bed, looking very ill. It’s only after she dies that Atticus reveals to his kids that Mrs. Dubose was a morphine addict and that in her final weeks she went cold turkey to kick her addiction. Part I ends with Atticus telling Jem that Mrs. Dubose was the bravest person he ever met.
In Part II, the focus of the novel shifts toward Tom Robinson’s trial, and the racism established in Part I intensifies. Scout and Jem, who have until now been shielded from the worst of it, see how segregation affects African Americans firsthand when Calpurnia takes them to her church, which is on the far side of town and called First Purchase. Atticus is out of town at this time, attending a meeting of the State Legislature, and doesn’t know about the church visit until after it happens. It prompts Aunt Alexandra, who has just moved into the Finches’ home, to scold Atticus for his lack of child-rearing skills. When Aunt Alexandra berates the kids about their manners and their lack of interest in their heritage, Atticus makes it clear that this is of no importance to him. This unites the Finch children against Aunt Alexandra.
Soon after Aunt Alexandra’s arrival, Scout discovers what she originally thinks is a snake under her bed, but which actually turns out to be Dill, who has run away from home because he doesn’t like his new stepfather. This incident adds a little levity to otherwise grim and serious events, like those of Chapter 15, when Atticus sits in front of the jail house to protect Tom Robinson from all the racist citizens of Maycomb. Late that night, a group of drunk men (some from Maycomb and some not) approach Atticus, intending, no doubt, to lynch Tom. Scout jumps in at the last second to save Atticus and stop the men, who are shamed by her presence. Thankfully, Mr. Underwood, the editor of The Maycomb Tribune, was standing watch over Atticus the whole time, carrying a double-barreled shotgun in case there was any trouble.
In the next chapter, Tom Robinson’s trial begins. It’s a “gala occasion,” as Scout puts it, and what seems like every person in Maycomb, black and white, comes to watch. Atticus spends the entire morning doing voir dire, or jury selection, and comes home for lunch around noon. Jem and Dill and Scout then decide—unbeknownst to Atticus—to go watch the trial that afternoon. As earlier, the courthouse is completely packed, and Scout and Jem have to climb up to the balcony with the Reverend Sykes to find seats in the “colored” section. Judge Taylor presides over the court and is impressively stern with the audience of people come to gawk at Tom. He threatens to fine people who don’t behave during the trial. Heck Tate is the first witness, and Atticus questions him about what he saw on the day of the alleged rape. Atticus trips him up a little when he asks if Mayella’s black eye was on the right or left side of her face. Heck Tate says left, then right. Then Mr. Ewell takes the stand and makes a show of accusing Tom of rape. Atticus then embarrasses him in front of everyone by proving that he’s left-handed and, thus, capable of giving Mayella a black eye on her right side. Jem finds this damning, but Scout doesn’t think it’s enough.
Next, Mayella takes the stand, afraid that Atticus will embarrass her like he did her father. Judge Taylor soothes her, though Jem suspects this is just a play for sympathy. Mayella, at nineteen and a half years old, is the eldest child in her family and has had to spend most of her time caring for her younger siblings, because her father certainly won’t. It’s a sad life, and Atticus makes a point of showing this to the audience, in the hopes that they’ll understand that her father, a drunk, is an antagonistic force in her life. Mayella has no friends. No money. No one to look out for her. And when she saw Tom Robinson, that polite man walking by her house on the way to work, Mayella invited him inside on the pretense of busting up a chiffarobe. Mayella says that’s when he started to choke her and beat her—with his right hand, not his left. Tom’s left arm hangs dead at his side, the product of an accident with a cotton gin. He couldn’t have given her that black eye, and that’s immediately clear when Mayella tells her story. It’s inconsistent with her father’s testimony. He’s lying, and so, Atticus suggests, is she.
When Tom takes the stand, the reader finally learns the truth: Mayella did lure him into the house with the promise of a nickel if he busted up a chiffarobe, but he never hurt her. In fact, she started coming onto him, moving in for a kiss, but when she saw her father in the window she screamed. Tom ran out of there as fast as he could, which made him look guilty, but he was innocent. It was Mr. Ewell who beat Mayella (and, presumably, raped her). Mr. Ewell blamed Tom for his crimes, both to keep him out of trouble and to save him from embarrassment, and Mayella does the same thing. Her reasons are somewhat different, though, because she doesn’t want anyone to know she tried to kiss an African American man. That’s taboo in racist Maycomb and would reflect poorly on her in court, which is why she’s so upset when Atticus tries to get the real truth out of her; she knows she can’t tell him. Tom knows that, too. He shouldn’t have helped her bust the chiffarobe, but he felt sorry for her. This upsets all the white people in the audience, because in their eyes, a black man has no right to feel sorry for a white person. When the prosecutor starts belittling Tom for this, Dill starts crying, and Scout has to take him outside.
Inside, Atticus makes his closing argument, telling the jury that Tom is innocent and that, even if they aren’t entirely convinced of this, they must be absolutely sure “beyond all reasonable doubt” that he’s guilty in order to convict him. Given what has come to light on the stand, it would seem impossible for them to have no doubts about Tom’s guilt, but this is Maycomb, Alabama, and the judge and jury are white, which means Tom’s apparent innocence isn’t enough to make up for the color of his skin in their eyes. That jury will never take the word of a black man over the word of a white one, regardless of how drunk, amoral, and ornery that white man is. Awkwardly, Atticus’ closing argument is interrupted by Calpurnia, who has come to inform him that his children have gone “missing.” Mr. Underwood informs them that the kids are in the balcony, and Atticus sends them home with Calpurnia to get their dinner. When they come back the jury is still out, which is in itself a victory. Had Atticus been less of a lawyer, the verdict would’ve been immediate. It’s a testament to his skill that the jury had to deliberate before giving the inevitable verdict: guilty.
The next morning, Atticus’ kitchen is full of gifts that the African American community sent him to show their gratitude to him for defending Tom. Miss Maudie, hearing about the verdict (as one of the few people who didn’t watch the trial), wakes up at five to bake the kids cake, in the hopes that this will make them feel a bit better. She suggests it was no accident Atticus was assigned to defend Tom—Judge Taylor might’ve done it on purpose to give Tom a fair shake. In fact, Atticus did so well that Mr. Ewell spits in his face outside the post office. As Atticus explains, race often comes between a person and their reason, making an otherwise logical or moral man turn into the kind of person who would, for instance, declare Tom guilty. At home, Atticus reveals to the kids that there was a Cunningham on the jury, and that this man wanted to acquit Tom, in part because Atticus had earned the Cunninghams’ respect that night outside the jail house. Scout reconsiders her dislike of Walter Cunningham because of this, but Aunt Alexandra balks when Scout asks if it would be alright for Walter to stay over at their house sometimes. Aunt Alexandra says Walter and the Cunninghams are “not [their] kind of folks.” It’s this behavior that leads Jem to say that he understands why Boo Radley stays inside: because he wants to.
In the aftermath of the trial, Aunt Alexandra attempts to return life to normal by hosting a lunch for her missionary circle. This proves to be an absurd experience for Scout, who’s forced to wear a dress, under which she defiantly continues to wear her britches. The ladies of the circle chat all afternoon about various hypocrites and Tom’s verdict, until finally Atticus comes home and says that Tom is dead—shot while attempting to escape from prison. Atticus and Calpurnia drive over to Tom’s house to give his wife, Helen, the news. Dill and Jem, who’d been out swimming at the time, rode in the car with Atticus and reported what they saw back to Scout. “She just fell down in the dirt,” Dill said, speaking of Helen when she heard the news. Everyone in Maycomb talked about it for a few days, then lost interest—except Mr. Underwood, who wrote an editorial saying that it’s a sin to kill a cripple. This echoes Atticus’ earlier statement about it being a sin to kill a mockingbird.
School starts up again in the fall, and with it, Jem and Scout’s daily trips past the Radleys’ house. Boo Radley has been largely absent from this second half of the book, and after Tom’s death, the kids aren’t really afraid of Boo anymore. Their lives revolve primarily around school and Atticus now. Scout relates a lesson her teacher gave on Adolf Hitler and democracy, defining the latter as “equal rights for all, special privileges for none.” This neatly frames the events of the subsequent chapter, in which Mr. Ewell stalks Helen in an attempt to intimidate her. This comes on the heels of Ewell getting and losing a job with the WPA and then attempting to break into Judge Taylor’s home in retribution for embarrassing him at the trial. Nobody thinks Ewell is dangerous, in large part because no one takes him seriously, and the town is more concerned with an incident where unknown assailants (children) sneak into the house of Misses Tutti and Frutti, two deaf women, and move all their furniture into their cellar one night. It appears for a moment that the novel is going to end on an easy note, with the children letting go of their superstitions, but Scout is still working up to how Jem broke his arm.
What happened was this: Scout was playing a ham in Maycomb’s Halloween pageant. No one in the immediate family was willing to see it but Jem, who walked her there in the dark, without his flashlight. On the way back, they hear a sound behind them and assume, at first, that it’s just one of Scout’s classmates trying to spook her. Then someone attacks them, and there’s a brief scuffle before the assailant, Mr. Ewell, falls, having been stabbed by Scout’s defender, Boo Radley, who carries Jem back to the house after his arm is broken. Scout doesn’t realize at first that this is her neighbor. Only after Dr. Reynolds arrives to take care of Jem and Heck Tate asks her to tell him what happened does Scout realize that the pale man standing in the corner is Boo. Atticus wants to tell people what Boo did and make him a hero, but Heck Tate tells him not to, calling it a “sin” to push such a shy man in the public’s eye. So they all keep Boo’s secret.
At the end of the novel, Scout walks Boo back to his house, stopping for a moment on his porch to look out at the town from his perspective: the children playing, leaves turning, Miss Maudie’s house burning. Scout tells Atticus that Boo was really nice. She has finally learned the lesson he tried to teach her earlier in the novel: that you can’t really understand a person until you walk in their shoes. Scout’s story may be about losing one’s innocence, but it’s also about coming of age, and that’s what makes this novel one of the most popular novels of all time.